diff options
| -rw-r--r-- | lib/stdlib/doc/src/gen_statem.xml | 5 | ||||
| -rw-r--r-- | lib/stdlib/src/gen_statem.erl | 116 |
2 files changed, 77 insertions, 44 deletions
diff --git a/lib/stdlib/doc/src/gen_statem.xml b/lib/stdlib/doc/src/gen_statem.xml index 567130875a..fd498ee82e 100644 --- a/lib/stdlib/doc/src/gen_statem.xml +++ b/lib/stdlib/doc/src/gen_statem.xml @@ -773,8 +773,9 @@ handle_event(_, _, State, Data) -> after this time (in milliseconds) unless another event arrives or has arrived in which case this time-out is cancelled. - Note that a retried, inserted or state time-out zero - events counts as arrived. + Note that a retried or inserted event counts as arrived. + So does a state time-out zero event, if it was generated + before this timer is requested. </p> <p> If the value is <c>infinity</c>, no timer is started, as diff --git a/lib/stdlib/src/gen_statem.erl b/lib/stdlib/src/gen_statem.erl index c81916197c..c9f8ec1881 100644 --- a/lib/stdlib/src/gen_statem.erl +++ b/lib/stdlib/src/gen_statem.erl @@ -1001,7 +1001,7 @@ loop_event_result( {sys_debug(Debug, S, State, {consume,Event,State}), P_0} end, - {Events_1,NewP,{TimerRefs,TimerTypes}} = + {Events_1,NewP,{TimerRefs_1,TimerTypes_1}} = %% Move all postponed events to queue and cancel the %% state timeout if the state changes if @@ -1012,17 +1012,16 @@ loop_event_result( cancel_timer_by_type( state_timeout, TimerRefs_0, TimerTypes_0)} end, - {NewTimerRefs,NewTimerTypes,TimeoutEvents} = - %% Stop and start timers - handle_timers(TimerRefs, TimerTypes, TimeoutsR), - %% Place next events first in reversed queue - NewEventsR = lists:reverse(Events_1, NextEventsR), - %% Append timeout zero events - NewEvents = - lists:reverse( - NewEventsR, - process_timeout_events(TimeoutEvents, NewEventsR)), - %% + {TimerRefs_2,TimerTypes_2,TimeoutEvents} = + %% Stop and start timers non-event timers + parse_timers(TimerRefs_1, TimerTypes_1, TimeoutsR), + %% Place next events last in reversed queue + Events_2R = lists:reverse(Events_1, NextEventsR), + %% Enqueue immediate timeout events and start event timer + {NewTimerRefs,NewTimerTypes,Events_3R} = + process_timeout_events( + TimerRefs_2, TimerTypes_2, TimeoutEvents, Events_2R), + NewEvents = lists:reverse(Events_3R), loop_events( Parent, NewDebug, S, NewTimerRefs, NewTimerTypes, NewEvents, Hibernate, NextState, NewData, NewP). @@ -1356,55 +1355,88 @@ parse_actions( %% Stop and start timers as well as create timeout zero events +%% and pending event timer %% -handle_timers(TimerRefs, TimerTypes, TimeoutsR) -> - Seen = #{}, - TimeoutEvents = [], - handle_timers(TimerRefs, TimerTypes, TimeoutsR, Seen, TimeoutEvents). +%% Stop and start timers non-event timers +parse_timers(TimerRefs, TimerTypes, TimeoutsR) -> + parse_timers(TimerRefs, TimerTypes, TimeoutsR, #{}, []). %% -handle_timers(TimerRefs, TimerTypes, [], _Seen, TimeoutEvents) -> +parse_timers(TimerRefs, TimerTypes, [], _Seen, TimeoutEvents) -> {TimerRefs,TimerTypes,TimeoutEvents}; -handle_timers(TimerRefs, TimerTypes, [Timeout|TimeoutsR], Seen, TimeoutEvents) -> +parse_timers( + TimerRefs, TimerTypes, [Timeout|TimeoutsR], Seen, TimeoutEvents) -> {TimerType,Time,TimerMsg} = Timeout, case Seen of #{TimerType := _} -> - handle_timers( + %% Type seen before - ignore + parse_timers( TimerRefs, TimerTypes, TimeoutsR, Seen, TimeoutEvents); #{} -> + %% Unseen type - handle NewSeen = Seen#{TimerType => true}, + %% Cancel any running timer {NewTimerRefs,NewTimerTypes} = cancel_timer_by_type(TimerType, TimerRefs, TimerTypes), - case Time of - 0 -> - TimeoutEvent = {TimerType,TimerMsg}, - handle_timers( - NewTimerRefs, NewTimerTypes, - TimeoutsR, NewSeen, [TimeoutEvent|TimeoutEvents]); - infinity -> + if + Time =:= infinity -> %% Ignore - timer will never fire - handle_timers( - NewTimerRefs, NewTimerTypes, - TimeoutsR, NewSeen, TimeoutEvents); - _ -> + parse_timers( + NewTimerRefs, NewTimerTypes, TimeoutsR, + NewSeen, TimeoutEvents); + TimerType =:= timeout -> + %% Handle event timer later + parse_timers( + NewTimerRefs, NewTimerTypes, TimeoutsR, + NewSeen, [Timeout|TimeoutEvents]); + Time =:= 0 -> + %% Handle zero time timeouts later + TimeoutEvent = {TimerType,TimerMsg}, + parse_timers( + NewTimerRefs, NewTimerTypes, TimeoutsR, + NewSeen, [TimeoutEvent|TimeoutEvents]); + true -> + %% Start a new timer TimerRef = erlang:start_timer(Time, self(), TimerMsg), - handle_timers( + parse_timers( NewTimerRefs#{TimerRef => TimerType}, NewTimerTypes#{TimerType => TimerRef}, TimeoutsR, NewSeen, TimeoutEvents) end end. - -%% Keep an event timeout event if it is the only event so far -process_timeout_events([], _Es) -> - []; -process_timeout_events([{timeout,_} = TimeoutEvent|TimeoutEvents], []) -> - [TimeoutEvent|process_timeout_events(TimeoutEvents, [TimeoutEvent])]; -process_timeout_events([{timeout,_}|TimeoutEvents], Es) -> - %% Ignore event timeout since there are other events - process_timeout_events(TimeoutEvents, Es); -process_timeout_events([TimeoutEvent|TimeoutEvents], Es) -> - [TimeoutEvent|process_timeout_events(TimeoutEvents, [TimeoutEvent|Es])]. +%% Enqueue immediate timeout events and start event timer +process_timeout_events(TimerRefs, TimerTypes, [], EventsR) -> + {TimerRefs, TimerTypes, EventsR}; +process_timeout_events( + TimerRefs, TimerTypes, + [{timeout,0,TimerMsg}|TimeoutEvents], []) -> + %% No enqueued events - insert a timeout zero event + TimeoutEvent = {timeout,TimerMsg}, + process_timeout_events( + TimerRefs, TimerTypes, + TimeoutEvents, [TimeoutEvent]); +process_timeout_events( + TimerRefs, TimerTypes, + [{timeout,Time,TimerMsg}], []) -> + %% No enqueued events - start event timer + TimerRef = erlang:start_timer(Time, self(), TimerMsg), + process_timeout_events( + TimerRefs#{TimerRef => timeout}, TimerTypes#{timeout => TimerRef}, + [], []); +process_timeout_events( + TimerRefs, TimerTypes, + [{timeout,_Time,_TimerMsg}|TimeoutEvents], EventsR) -> + %% There will be some other event so optimize by not starting + %% an event timer to just have to cancel it again + process_timeout_events( + TimerRefs, TimerTypes, + TimeoutEvents, EventsR); +process_timeout_events( + TimerRefs, TimerTypes, + [{_TimeoutType,_TimeoutMsg} = TimeoutEvent|TimeoutEvents], EventsR) -> + process_timeout_events( + TimerRefs, TimerTypes, + TimeoutEvents, [TimeoutEvent|EventsR]). |